This invention related to a jig, or device for holding a long-type shaped product (or products) of ceramics when it is dried. More particularly, this invention is concerned with a device which enables the drying of any such product in such a way that it may maintain a high degree of dimensional accuracy and may not be undesirably deformed.
An extruded or otherwise shaped product of ceramics, especially a long-type one having a large length and a small wall thickness or diameter, such as a ceramic tube or rod, is liable to deformation by its own weight before it is dried, though it retains a definite shape after it has been dried. Various methods have, therefore, been proposed for restraining such deformation. According to the disclosure of Japanese Patent Publication No. 27163/1988, an elongated extruded product is received on a supporting plate and is dried by blowing, for example, hot air from a means for air supply connected to the supporting plate. According to the disclosure of the Japanese patent application laid open to the public under No. 110291/1988, an extruded tube is dried on a porous support having a recessed portion.
Although both of these methods can prevent the deformation of a long-type shaped product, such as a tube, by its own weight, they are unsatisfactory for other reasons. If the former method is employed for drying an extruded product by hot air, etc., it is likely that localized drying of the product in its surface portion will occur and may strain it and cause it to have defects such as cracks. Moreover, it is likely that, whichever method may be employed, the product may not be dried completely, but may thereafter require additionally drying. The additional drying of the product causes it to be curved along its length. Therefore, none of the known methods is suitable for making a shaped member which requires a very high level of dimensional accuracy.